In that post, we asked our readers if any of them were barefoot runners or had tried the Vibram five-finger shoes. We were happy to receive a response the next day from a long-time barefoot runner, Leif Rustvold, known to many as "Zeke."

Jim RustvoldRustvold at the 2010 Rock 'n' Roll 50K in Phoenix - barefoot - where his 4:15 finish earned him a 50k PR.

Rustvold, a barefoot/minimalist ultramarathoner, is a biological anthropologist that lives in Portland, Oregon. As a biological anthropologist, he studies the way in which humans biologically changed or adapted to their surroundings over time. So he is understandably passionate about the discussion around the ways in which running shoes affect a runner's natural stride and movement. "I've been thrilled to see this conversation blossom in the last year," he says.

His minimalist running style doesn't mean he's running around barefoot everywhere he goes. While barefoot is his preferred mode of transport when running on the road, he slides on a pair of Vibram Five-Fingers for trail to protect his feet.

He didn't just show up for a marathon and decide to try it out barefoot. Rustvold started out occasionally going for short barefoot runs for a couple of years. When Vibram came out with their Five-Finger Sprints in 2007, Rustvold got a pair and started adding distance. Wearing the Five-Fingers, he worked up to running a distance of around 6 miles each week. The shift to minimal footwear gave him time for his form and footstrike to be rehabilitated to what was more natural.

He says of the change, "It lets me run like a human, which is exciting, fun, and exhilarating.

Because it is squarely in line with how we evolved rather than being pushed outside of our well optimized gait, I believe it is more ergonomic and therefore less conducive to injury."

Once running in the Five-Fingers became comfortable for him, he started running all of his short runs in them - anything shorter than a 10k was done in the minimal footwear. His definition of "short" changed to include longer and longer runs, and in September 2009 he ran a 100-mile trail run in the Five-Fingers.

During that time, Rustvold added in some actual barefoot running. He credits the transition with the Five-Fingers for allowing him to ease into barefoot running more successfully. "Because I had rehabilitated my feet and form in VFFs," he explains, getting used to running barefoot only "took a little more refinement of my form and a bit of time for the skin of my soles to thicken."

Just one week after the 100-mile trail run in the Five-Fingers, he ran a marathon in his bare feet. And this past January, he added a barefoot ultra to his resume with the Rock 'n' Roll 50k in Phoenix, Arizona.

As with many barefoot runners, Rustvold's nude feet spark comments and even pointing from time to time. But he won't trade it back to running in shoes for anything. "It totally changes the sport of running. Everything I love about running is enhanced by being barefoot. The mental awareness of being barefoot encourages/requires you to ditch the iPod and listen to your inner dialogue." Rustvold finds himself reaching a "runner's high" more efficiently, having more fun, and the movement feels more natural and less likely to cause injury. While there are still the occasional minor injuries from stepping on a sharp rock, he sees it as a fair trade-off for the reduction in major injuries.

Rustvold chronicles his barefoot running on his blog, Distance Minimally. You can read archived posts to follow his progressing from the Vibram Five Fingers to running a barefoot ultra: